Mauna Loa Quake Triggers Tsunami Warning No Tsunami After 6.0 Shake
A tsunami warning was not issued after a magnitude 6.0 earthquake struck the western flank of Mauna Loa on Hawaii island at 9:46 p.m. on Monday night. The U.S. Geological Survey upgraded the quake from an initial magnitude 5.9, and the Pacific Tsunami Warning Center later said the event did not generate a tsunami.
The earthquake was centered about 8 miles south of Honaunau-Napoopoo and about 22 miles south-southeast of Kailua-Kona, at a depth of about 15 miles. The same agency said some areas may have felt strong shaking, and the quake was felt across the islands, including Maui and Oahu.
USGS Upgrade on Hawaii Island
The upgraded magnitude put the quake in the strong range. A magnitude 6 earthquake can cause light property damage, and the USGS 'Did you feel it?' online survey recorded dozens of immediate responses, including reports from Lahaina and Mililani.
About six minutes after the main quake, a magnitude 3.2 aftershock hit the same area. That second jolt reinforced the immediate focus on whether the shaking would produce any broader hazard, but the Pacific Tsunami Warning Center said it did not.
Pacific Tsunami Warning Center Assessment
The Pacific Tsunami Warning Center's assessment resolved the main public safety question for Hawaii island and nearby islands: the quake did not generate a tsunami. The strongest shaking was concentrated near Mauna Loa's western flank, while the reports from Maui and Oahu showed how widely the tremor was felt.
For people on Hawaii island and across the islands, the practical takeaway is that the strongest impact from Monday night's quake was the shaking itself, not a tsunami. The next development in the sequence was the aftershock six minutes later, which added another brief burst of movement before the alert concern faded.
